The Centers for Medicare and Medicaid Services have become increasingly focused on improving healthcare safety and quality while decreasing costs and adopted a policy of no longer reimbursing hospitals for the costs of treating designated preventable inpatient complications. Living donor liver transplantation (LDLT), involves complex systems and processes of care that are particularly vulnerable to medical errors and preventable complications. In fact, complication rates for LDLT donors and recipients are 20-30% and 75%, respectively, of which 70% are deemed preventable. Effective elimination of preventable complications in LDLT will require careful attention to the vulnerabilities in the systems and processes of care for LDLT donors and recipients. Prevention of such events is especially important when caring for living donors, given that they are healthy volunteers undergoing a major procedure purely for altruistic reasons without any direct benefit. The importance of donor safety is magnified in light of the two LDLT donor deaths, earlier this year in the United States. Considerable advances in reducing medical errors and preventable complications have already been achieved. In the field of transplantation, new protocols such as those used to confirm ABO compatibility between the donor and recipient have been highly effective. This study proposes to apply the proactive, systematic, and comprehensive approaches successfully used in other high risk industries and adapted for healthcare, to LDLT system and processes of care. The proactive, systematic, and comprehensive identification of potential vulnerabilities will permit the development and implementation of solutions designed to mitigate these vulnerabilities and, thus, reduce medical errors and preventable complications in LDLT. This study will build on the considerable strengths of the Adult-to-Adult Living Liver Transplant Cohort Study (A2ALL) as an ancillary study of the A2ALL consortium. A2ALL has recognized the importance of providing safe and reliable LDLT care, and has made donor safety a secondary aim and fully supports this study. Seven of the nine A2ALL centers will be involved in this study either as an intervention or a control center, thus, representing more than 50% of all LDLTs performed in the US. This study is novel and innovative, because it seeks to shift the paradigm of response to medical errors to a proactive approach of assessing and improving the safety of systems and processes to prevent medical errors in living donor liver transplant (LDLT) before they occur. This study will apply adapted methods successfully applied by other high risk industries to generate new and important information about LDLT safety. LDLT provides an excellent opportunity to fully assess the mechanisms of medical errors and preventable complications as there is little risk of confounding by donor co-morbid conditions.